Recently, the development of image display technology changes continuously and therefore liquid crystal display, which is thin and light and has low electromagnetic radiation, has become the mainstream product in the display market gradually. In the current double gate liquid crystal display device, the distance between the pixel electrodes is small because of the demand of pixel aperture ratio, such that electric conductance may happen between different pixel electrodes and cause short circuit because the pixel electrode residues may be generated in the gap between the pixel electrodes easily or foreign substances for example particles may fall into the gap between the pixel electrodes during the manufacturing procedure.
For example, FIGS. 1 and 2 illustrate a layout diagram and a cross-sectional view of a thin film transistor substrate of a traditional double gate liquid crystal display device. FIG. 2 is a cross-sectional view of FIG. 1 taken along line A-A′. Irrelevant descriptions are omitted to prevent obscuring the focus because the aforementioned prior art primarily describe the pixel electrodes and the related features thereof. Wires 102 are formed on a glass substrate 101, and a dielectric layer 103 is formed on the wires 102 and the glass substrate 101. The pixel electrodes 104 are further formed on the dielectric layer 103, and a gap 105 is formed between the pixel electrodes 104. As shown in FIGS. 3 and 4, when the pixel electrode residues are generated in the gap 105 or the foreign substances fall into the gap 105 during the manufacturing procedures, the residue 106 is formed in the gap 105 between the pixel electrodes 104. FIG. 4 is a cross-sectional view of FIG. 3 taken along line A-A′. As shown in FIG. 5, to solve the short circuit problem caused by the residue 106, the traditional repairing method utilizes laser beam 108 to aim at the residue 106 to cut off the residue 106. However, if the aforementioned repairing method is utilized to repair the traditional double gate liquid crystal display device, several problems will happen. For example, with reference to FIG. 4, when the energy of the laser beam 108 is too high, the laser beam 108 will continue to downwardly cut the underlying layer after the residue 106 is cut off. Therefore, the wires 102 will be damaged by the laser beam 108, such that light leakage problem will happen. Otherwise, when the energy of the laser beam 108 is too low, only part of the residue 106 is cut. Therefore, the residue 106 will flow down to the wires 102 because of melting state, and the residue 106 will weld with the wires 102. Therefore, the adjacent pixel electrodes 104 will keep electrically conducted with each other through the welding between the residue 106 and the wires 102, such that the short circuit problem cannot be solved.
Furthermore, a color filter substrate (not shown) is disposed on the thin film transistor substrate of the traditional double gate liquid crystal display device. A black matrix (BM) (not shown) is disposed on the color filter substrate. The black matrix is disposed in the position aligning with the wires 102 and the gap 105 between the pixel electrodes 104. Therefore, the gap 105 between the pixel electrodes 104 cannot be seen from the viewpoint above the liquid crystal display device. In other words, whether the residue 106 exists in the gap 105 or not cannot be observed from the viewpoint above the liquid crystal display device, and where the residue 106 is cannot be observed from the viewpoint above the liquid crystal display device, neither. Moreover, as shown in FIG. 4, the gap 105 between the pixel electrodes 104 cannot be seen from the viewpoint below the liquid crystal display device because the wires 102 are disposed below the gap 105 between the pixel electrodes 104. In other words, whether the residue 106 exists in the gap 105 or not cannot be observed from the viewpoint below the liquid crystal display device, and where the residue 106 is cannot be observed from the viewpoint below the liquid crystal display device, neither. Therefore, whether the residue exists or not and where the residue is cannot be identified when defective points caused by the pixel electrode residues or foreign substances are being repaired. Accordingly, there is still a need for a liquid crystal display device which can solve the aforementioned problems.